| 摘要: |
| 橡胶坝是一种低水头轻性薄壳柔体挡水建筑物，结构简单、施工方便且造价低廉，修建橡胶坝拦水造湖可形成景观水面，但立坝运行会造成库区床面的泥沙淤积，因此遵循河床演变规律，合理运行橡胶坝，可保持库区长期可利用库容。采用MIKE软件模拟桃花潭库区10年水沙条件下的河床演变，综合考察桃花潭河段水流流场、床面淤积厚度、河床比降以及纵断面形态的变化。结果表明：桃花潭河段的冲淤平衡年限约为7年，平衡后主河道淤积较为严重；冲淤平衡后河床纵断面在展宽段呈向上凸起的河床形态；基于桃花潭河段的几何特性、来水来沙条件和由宽入窄的壅水作用，进入该河段的含沙水流会因河道突然展宽，水流挟沙力与水流动能减小，导致泥沙更易淤积，造成床面抬升和洪水位的抬高。 |
| 关键词: 橡胶坝 数值模拟 河床演变 淤积厚度 河床比降 平衡年限 |
| DOI： |
| 分类号:TV133.1 |
| 基金项目:国家重点基础研究发展计划（973）资助项目（2011CB403305）； 陕西省教育厅科学研究计划项目（11JK0739）； 陕西水利科技计划资助项目（2014skj-14） |
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| Two-dimensionl numerical simulation of riverbed evolution of Taohuatan in the Chan River |
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WEI Bing-qian1, YAN Pei1, PANG Jie1, LIU Yang2, ZHOU Shuang-ming1, LI Qiang3
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1.College of Hydraulic and Hydropower, Xi’an University of Technology, Xi’an;2.Jiangxi Provincial Water Conservancy Planning and Designing Institute,Nanchang;3.Key Laboratory of Port, Waterway and Sedimentation Engineering of the Ministry of Transport, Nanjing Hydraulic Research Institute
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| Abstract: |
| The rubber dam is a kind of water-retaining structure which has the advantages of low head, thin shell, flexible body, simple structure, convenient construction and low cost. Landscaped watercourse has been formed after building the rubber dam, which is used to retain and make lakes. But the operation of the dam will cause sedimentation in the upstream reservoir. Therefore, reasonable operation of the rubber dam is needed so as to maintain an ideal reservoir storage capacity for a long time. In this study, sediment calculation is made for ten years design for water and sediment conditions by using MIKE software, and the simulation of bed evolution is conducted to study the sediment deposition of Taohuatan reach in the Chan River. A comprehensive survey is made to show the changes of the flow field, aggradation thickness of the bed surface, river gradient and the vertical morphology of the river bed profile. What can be concluded from the result is that: the equilibrium for scouring and siltation in the reservoir of Taohuatan can be reached at about the seventh year, and the siltation in the main channel reach is rather serious; the river bed profile at the broadening reach is slightly convex upward after the scouring and siltation are in the state of equilibrium on the whole; on the basis of the geometric characteristics, the effect of the incoming water and sediment, and the backwater effect of flowing from wide channel to narrow one, the entering sediment laden flow will decrease due to the sudden widening of the river, which will lead to the reduction of sediment carrying capacity of flow and flow energy, hence resulting in easier siltation, higher bed surface, and higher flood water level. |
| Key words: rubber dam numerical simulation bed evolution deposition thickness bed gradient equilibrum year |
